Receptacle assembly having shielded receptacle connector interface with pluggable electronic module

ABSTRACT

A receptacle assembly includes a guide frame having a front end with an opening to an interior cavity of the guide frame. The opening is configured to receive a module assembly. The guide frame has a bottom with a bottom opening to the interior cavity, and the bottom is configured to be joined to a circuit board. An EMI gasket is provided along at least a portion of a perimeter of the bottom opening to be held between the guide frame and a circuit board. The EMI gasket forms a shielded interface along the portion of the perimeter of the bottom opening. Conductive straps are provided along the leading edge of the opening and have widths sufficient to cover a substantial majority of the leading edge to form a shielded interface along the leading edge. An EMI gasket including a skirt extending partially along a portion of the perimeter of the bottom opening is also provided.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/362,185 filed Mar. 6, 2002 and U.S. Provisional Patent ApplicationNo. 60/372,861 filed Apr. 16, 2002, each of which is hereby incorporatedby reference in its entirety.

BACKGROUND OF THE INVENTION

The invention relates generally to an electronic transceiver assembly,and more particularly, to a receptacle which is mounted on a circuitboard and a transceiver module pluggable into the receptacle.

Various types of fiber optic and copper based transceivers that permitcommunication between electronic host equipment and external devices areknown. These transceivers may be incorporated into modules that can bepluggably connected to the host equipment to provide flexibility insystem configuration. The modules are constructed according to variousstandards for size and compatibility, one standard being the SmallForm-factor Pluggable (SFP) module standard.

The SFP module is plugged into a receptacle that is mounted on a circuitboard within the host equipment. The receptacle includes an elongatedguide frame, or cage, having a front that is open to an interior space,and an electrical connector disposed at a rear of the cage within theinterior space. Both the connector and the guide frame are electricallyand mechanically connected to the circuit board, and when an SFP moduleis plugged into a receptacle it is electrically and mechanicallyconnected to the circuit board as well. Conventional SFP modules andreceptacles perform satisfactorily carrying data signals at rates up to2.5 gigabits per second (Gbps).

A standard currently in development for a next generation of SFPmodules, presently being called the XFP standard, calls for thetransceiver modules to carry data signals at rates up to 10 Gbps. Thetransceiver modules will encounter several problems at the increaseddata rate not experienced previously. One problem is that thetransceiver modules and the surrounding circuitry will generatesignificantly greater quantities of heat to be removed in order for theelectronic components to survive long term. Another problem is that thetransceiver modules will generate increased quantities ofelectromagnetic (EM) energy at very short wavelengths. As the EM energyat the short wavelengths increases, the potential exists for more EMenergy to pass through gaps in the shielding of the receptacle or guideframe. As more EM energy is accepted through the receptacle, the datasignals conveyed by adjacent transceiver modules experience more EMinterference (EMI). It is desirable to shield or isolate the datasignals from EMI to the extent practical.

Further, conventional transceiver module assemblies include latchmechanisms to secure the transceiver module in the receptacle and toeject the transceiver module from the receptacle. It is desirable toprovide a latch mechanism that is reliable, secure and robust.

There is a need to improve the design of a pluggable electronic moduleand receptacle in order to overcome present deficiencies and anticipatedproblems, among other things, due to higher data rates.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with an exemplary embodiment of the invention, areceptacle assembly is provided. The assembly comprises a guide framehaving a front end with an opening to an interior cavity of the guideframe. The opening is configured to receive a module assembly. The guideframe has a bottom with a bottom opening to the interior cavity, and thebottom is configured to be joined to a circuit board. An EMI gasket isprovided along at least a portion of a perimeter of the bottom openingto be held between the guide frame and a circuit board. The EMI gasketforms a shielded interface along the portion of the perimeter of thebottom opening.

In an exemplary embodiment, the EMI gasket includes a series ofconductive straps provided along a leading edge of the bottom openingnearest the front end. The conductive straps are provided along theleading edge and have widths sufficient to cover a substantial majorityof the leading edge to form a shielded interface along the leading edge.An EMI gasket including a skirt extending partially along a portion ofthe perimeter of the bottom opening is also provided, and the skirt isformed of a rubber elastomer containing conductive particulate material.

In accordance with another exemplary embodiment of the invention, atransceiver receptacle assembly is provided. A guide frame has a frontend with an opening to an interior cavity of the guide frame, and theopening is configured to receive a transceiver module assembly. Theguide frame has a bottom with a bottom opening to the interior cavity,and the bottom is configured to be mounted to a conductive layerprovided on a circuit board. The bottom opening is configured to receivea receptacle connector mounted to the printed circuit board. An EMIgasket is provided along at least a portion of an edge of the bottomopening, and the EMI gasket is compressible between the guide frame andthe conductive layer on the circuit board.

The EMI gasket includes conductive straps provided along one edge of thebottom opening, and conductive straps are deflectable by the transceivermodule assembly to directly engage the conductive layer of the circuitboard. Separate gaskets are provided on the remaining edges of thebottom opening. The guide frame is mounted to the circuit board with thereceptacle connector extending upward into the bottom opening, and theEMI gaskets surround the receptacle connector.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a module assembly and areceptacle assembly formed in accordance with an embodiment of theinvention.

FIG. 2 is a bottom perspective view of the heat sink shown in FIG. 1.

FIG. 3 is an assembled perspective view of a portion of the assemblyshown in FIG. 1, showing the module assembly in a latched positionwithin the receptacle assembly.

FIG. 4 is a cross sectional view of the assembly illustrated in FIG. 3taken along line 4—4.

FIG. 5 is a perspective view of the assembly shown in FIG. 2 in anunlatched position.

FIG. 6 is a partly broken away perspective view of the receptacleassembly shown in FIGS. 1 and 3-5.

FIG. 7 is a perspective view of a clip for the assembly shown in FIG. 1.

FIG. 8 is a perspective view of a heat sink assembly formed inaccordance with an embodiment of the invention.

FIG. 9 is a side elevational view, partly broken away, of the heat sinkassembly shown in FIG. 8 attached to the receptacle assembly.

FIG. 10 illustrates another heat sink assembly attached to a receptacleassembly formed in accordance with an alternative embodiment of thepresent invention.

FIG. 11 illustrates a module interface of the receptacle assemblyincluding an electromagnetic interference shielding gasket assemblyformed in accordance with an embodiment of the invention.

FIG. 12 is a perspective view of a collar for the gasket assembly shownin FIG. 12.

FIG. 13 is a cross sectional view of the gasket assembly shown in FIG.11 installed on the receptacle assembly.

FIG. 14 is a perspective view of an alternative embodiment of moduleinterface of a receptacle assembly.

FIG. 15 is a bottom perspective assembly view of the circuit boardinterface of the receptacle assembly including an electromagneticinterference shielding gasket assembly formed in accordance with anembodiment of the invention.

FIG. 16 is a front perspective assembly view of the module assemblyshown in FIGS. 1 and 3-5 illustrating an ejector mechanism formed inaccordance with an embodiment of the invention.

FIG. 17 is a side elevational view of the module assembly illustratingthe ejector mechanism in a latched position.

FIG. 18 is a side elevational view of the module assembly illustratingthe ejector mechanism in a first intermediate position.

FIG. 19 is a side elevational view of the module assembly illustratingthe ejector mechanism in a second intermediate position.

FIG. 20 is a side elevational view of the module assembly illustratingthe ejector mechanism in an unlatched position.

FIG. 21 is an exploded assembly view of a second embodiment of anejector mechanism for a module assembly.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a module assembly and receptacle assembly 100 formedin accordance with an exemplary embodiment of the invention. For thereasons set forth in detail below, assembly 100 is adapted to address,among other things, heat dissipation and electromagnetic shielding forcomponents conveying data signals at high rates, such as datatransmission rates of 10 gigabits per second (Gbs). It is appreciated,however, that the benefits and advantages of the invention may accrueequally to other data transmission rates and across a variety of systemsand standards. Therefore, while the invention is described andillustrated in the context of assembly 100, the invention is notintended to be limited to assembly 100, and assembly 100 is thereforeprovided for purposes of illustration rather than limitation.

As shown in FIG. 1, assembly 100 generally includes a module assembly102 configured for pluggable insertion into a receptacle assembly 104that is mounted to a host circuit board 106, which, in turn, is mountedin a host system such as a router or computer (not shown). The hostsystem typically includes a conductive chassis having a bezel 108including openings 109 therethrough in substantial alignment with arespective receptacle assembly 104. The module assembly 102 is insertedinto the receptacle assembly 104 through the bezel opening 109, and thereceptacle assembly 104 is electrically connected to the bezel 108.

In an illustrative embodiment, the module assembly 102 includes ahousing 110 including a base 112 and a cover 114 that are securedtogether to form a protective shell for a circuit board (not shown inFIG. 1) that is disposed within the housing 110. The circuit boardcarries electronic circuitry and devices that perform transceiverfunctions in a known manner. An edge of the circuit board is exposedthrough a rear 116 of the housing 110, and the circuit board edge ispluggable into the receptacle assembly 104 as described below. Themodule assembly 102 is adapted for installation into the receptacleassembly 104 such that a front end 118 of the module assembly 102 isextended therefrom.

The module assembly 102 is configured to be inserted into the receptacleassembly 104. In general, the module assembly 102 and receptacleassembly 104 may be used in any application requiring an interfacebetween a host system and electrical or optical signals. The moduleassembly 102 interfaces to the host system through the receptacleassembly 104 via a receptacle connector 120 which is located within areceptacle guide frame 122, also referred to as a cage. The moduleassembly 102 interfaces to an optical fiber or electrical cable (notshown) through a connector interface 124 at a front end 118 of themodule assembly 102. Preferably, the connector interface 124 comprises amechanism that cooperates with a fiber or cable assembly to secure thefiber or cable assembly to the module assembly 102. Suitable connectorinterfaces 124 are known and include adapters for the LC styleconnectors and the HSSDC2 copper connectors offered by Tyco ElectronicsCorporation (Harrisburg, Pa.).

The module assembly 102 and the receptacle assembly 104 reduce EMIemission through one or more of several EMI reduction features,including guide frame 122, a gasket assembly 125 coupled to a forwardend of the guide frame 122 that interfaces with bezel 108, andintermediate and rear gasket assemblies 123, 125, all described below inmore detail.

As illustrated in FIG. 1, the guide frame 122 includes a stamped andformed metal body 126 that defines a shell having a top wall 128, abottom wall 130, and side walls 132, 134. Front edges of each of thetop, bottom and side walls 128-134 are formed as flanges which surrounda front opening 136 into the guide frame 122. The top wall 128, thebottom wall 130, and the side walls 132, 134 define a cavity 138therebetween for receiving the module assembly 102 through an opening136 in the front end of the guide frame 122. The bottom wall 130 has abottom opening to receive the receptacle connector 120. The guide frame122 has a positive stop 140, which engages a surface of the moduleassembly 102 to prevent the module assembly 102 from passing too farrearwardly through the guide frame 122. When the module assembly 102 isinserted into the receptacle assembly 104, the guide frame 122 providesconductive walls on all sides thereof. Bottom wall 130 of guide frame122 includes compliant pin leads 142 that are received withinthrough-holes 144 of the host board 106 and provide a conductive path toground of an equipment chassis when the receptacle assembly 104 ismounted therein. Host board 106 includes a conductive surface 146provided thereon and formed as a sheet to underlie receptacle assembly104 to enhance the electromagnetic interference shielding.

The receptacle connector 120 is mounted on the circuit board 106 of thehost equipment along with the guide frame 122, but separated fromconductive surface 146 of host board 106. The receptacle connector 120may be, for example, that which is sold under part number 788862-1 byTyco Electronics Corporation. The receptacle connector 120 includes aslot that receives an edge of the circuit board that is carried by themodule assembly 102 when the module assembly 102 is fully installed inthe guide frame 122, thereby electrically connecting the module assembly102 to the host equipment.

The top wall 128 of the guide frame 122 has a large opening 194overlying cavity 138 that accommodates a heat sink 150. The heat sink150 is positioned to make physical contact with the module assembly 102when the module assembly 102 is installed into the receptacle assembly104. A clip 152 is mounted over the heat sink 150 and is secured to theguide frame 122. The clip 152 ensures that the heat sink 150 is loadedagainst the module assembly 102 to facilitate thermal transfer from themodule assembly 102 to the heat sink 150. The heat sink 150 includes anengagement surface (described below) that faces and is located proximatethe interior cavity 138 of the guide frame 122. The engagement surfaceof the heat sink 150 is configured to physically contact and abutagainst the module assembly 102 when installed in the interior cavity138.

A retention tab 154 is formed on each of the side walls 132, 134 of theguide frame 122. The retention tabs 154 engage the clip 152 which, inturn, retains the heat sink 150 on the guide frame 122. Clip 152securely engages the guide frame 122 to retain the heat sink 150 uponthe guide frame 122. The clip 152 includes resilient spring members 155secured over heat sink 150. The spring members 155 flex to permit theheat sink 150 to move outward away from the guide frame 122 when themodule assembly 102 is installed. The spring members 155 exert a desiredforce against the heat sink 150 to maintain a desired abutting interfaceto facilitate thermal transfer and heat dissipation from the moduleassembly 102. The clip 152 further includes side rails 156 that snapover the side walls 132, 134 of the guide frame 122. The side rails 156are joined to one another by spring members 155 that extend over, andflexibly engage, the heat sink 150.

FIG. 2 illustrates a bottom perspective view of heat sink 150 includinga peripheral outer surface 160 and module engagement surface 162 that isstepped relative to the peripheral surface 160 to extend into theinterior cavity 138 of the guide frame 122. The peripheral surface 160surrounds the engagement surface 162 on the periphery or perimeter 163thereof, and the peripheral surface 160 is recessed relative to a planeextending through the engagement surface 162. In one embodiment, theengagement surface 162 is approximately centered within the peripheralsurface 160, and a ramped transition portion 164 extends on each of theleading edges 168, 170 of the engagement surface 162. Notched or cut outportions 170 are formed in the longitudinal side walls of the heat sink150 to accommodate clip 152 (shown in FIG. 1) when the heat sink 150 isinstalled.

The engagement surface 162 of the heat sink 150 rests within theinterior cavity 138 of the guide frame 122 at a level that interfereswith an installation path of the module assembly 102. The heat sink 150is moved outward by the module assembly 102, as further described below,when the module assembly 102 is installed to provide an abuttinginterface between the heat sink 150 and the module assembly 102.

Returning to FIG. 1, when the module assembly 102 is removed, theengagement surface 162 of the heat sink 150 rests within the interiorcavity 138 of the guide frame 122 at a level that interferes with aninstallation path of the module assembly 102. The heat sink 150 ismovable outward by the module assembly 102 when the module assembly 102is installed to provide an abutting interface between the heat sink 150and module assembly 102. The engagement surface 162 of the heat sink 150is flat and smooth to slide along a mating surface of the moduleassembly 102 when the module assembly 102 is installed.

In a further and/or alternative embodiment, a thermal interface material(not shown) is disposed on the engagement surface 162 of the heat sink150 and the cover 114 of the module assembly 102. The thermal materialis compressed between the engagement surface 162 of the heat sink 150and the cover 114 when the module assembly 102 is installed. In such anembodiment, in order to avoid abrasion and damage to the thermalinterface material as the module assembly 102 is installed into theguide frame 122, an underside of the heat sink 150 may include an arrayof bosses that correspond with an array of apertures in a top surface ofthe module assembly 102. The bosses may slide along the top surface ofthe module assembly 102 and serve as standoffs to maintain the thermalinterface material at a specified height above the module assembly 102as the module assembly 102 is being installed into the guide frame 122.When the module assembly 102 is fully inserted into the guide frame 122,the bosses are aligned with and engage the apertures, therebycompressing the thermal interface material between the module assembly102 and the heat sink 150, which promotes heat transfer.

FIG. 3 is a perspective view of receptacle assembly 104 mounted to thehost board 106 and receiving the module assembly 102, with heat sink 150and clip 152 removed for clarity. Also, bezel 108 is not shown in FIG.3.

Module assembly 102 is illustrated in a latched position wherein removalfrom the guide frame 122 is prevented. An axial pull on the front end118 of the module assembly 102 in the direction of arrow A, whenlatched, is ineffective to remove the module assembly 102. In thelatched position, front end 118 of the module assembly 102 extends orprotrudes outwardly a specified distance from an EMI gasket collar 231which is positioned in abutting contact with an interior surface (notshown in FIG. 3) of bezel 108 (shown in FIG. 1) in use. Bezel 108includes a gasket 233, described below in relation to FIG. 4, that ispermanently fastened thereto, and the collar 231 is positioned incontact with the gasket 233 for EMI shielding. Referring back to FIG. 3,the module assembly 102 is extended through collar 231 and guide frame122. An ejector mechanism 180 is provided on the front end 118 of moduleassembly 102 and includes a rotatably mounted bail 182 and spring-loadedactuator arms 184 extending on opposite sides thereof in a generallyparallel direction to the side walls 132, 134 of guide frame 122.Construction and operation of ejector mechanism 180 is described below.

Guide frame 122 includes a conductive body 126 that is formed from ametallic sheet plated with tin/lead in an exemplary embodiment. The body126 is formed into a shell having a top wall 128, a bottom wall 130, andside walls 132, 134. The top wall 128, the bottom wall 130, and the sidewalls 132, 134 define the cavity 138 (shown in FIG. 1) in which moduleassembly 102 is received.

The top wall 128 of the guide frame 122 includes a front portion 186, arear portion 188, and opposed lateral portions 190, 192 that define aperimeter of the opening 194. The portions 186-192 of the top wall 128also define a maximum distance that the heat sink 150 (shown in FIGS. 1and 2) extends into the interior cavity 138 (shown in FIG. 1) in whichthe module assembly 102 is contained. The top wall 128 supports the heatsink 150 when the heat sink 150 is mounted over the opening 194.Retention tabs 154 are punched from each of the respective side walls132, 134 and bent outwardly. Tabs 154 engage mating openings 198 in theside rails 156 (shown in FIG. 1) in clip 152 (also shown in FIG. 1) whenthe heat sink 150 is attached to guide frame 122. In an exemplaryembodiment, tabs 154 are triangular in shape, which restricts the clip152 from movement in both a vertical and horizontal direction relativeto the guide frame 122, although it is recognized that other shapes fortabs 154 may be employed.

The rear portion 188 of the top wall 128 includes positive stops 140 inthe form of downwardly extending tabs that project slightly inward intoopening 194 and downward into cavity 138. The stops 140 engage a rearsurface of the module assembly 102 to prevent the module assembly 102from passing rearwardly through the guide frame 122 beyond a specifieddistance. Each of the side walls 132, 134 of the guide frame 122includes a latch element 196 that engages a respective actuator arm 184of ejector mechanism 180. In the illustrated embodiment, latch elements196 are rectangular tabs punched from the respective side walls 132, 134and bent inwardly into the interior of the cavity 138 of the guide frame122. When module assembly 102 is inserted in the guide frame 122, latchelements 196 contact the side outer surfaces of the housing 110 (shownin FIG. 1) of the module assembly 102 and resiliently deflect outwardlyto permit insertion of the module assembly 102. Once the module assembly102 is inserted a predetermined distance into the guide frame 122, thelatch elements 196 return to the latched position illustrated in FIG. 3in engagement with the actuator arms 184.

FIG. 4 is a cross sectional view of the module assembly 102 coupled tothe receptacle assembly 104 with the module assembly 102 in the latchedposition. The module assembly 102 includes a printed circuit board 220therein. An end 222 of the printed circuit board 220 is received in aslot 224 of the receptacle connector 120 which is mechanically andelectrically mounted to the host board 106. The receptacle connector 120includes electrical contacts 226 that contact conductive terminations onthe end of the printed circuit board 220 to establish electricalconnection to conductive paths on the host board 106. When the moduleassembly 102 is inserted in to the guide frame 122, the end 222 of theprinted circuit board 220 is inserted into the connector slot 224, andwhen the module assembly 102 is fully inserted into the guide frame 122,the module assembly 102 is locked in the latched position with theprinted circuit board 220 fully engaged to the receptacle connector 120.

FIGS. 4 and 11-13 illustrate resilient metal spring gaskets 228, 230that are provided in the forward end of the guide frame 122 proximate aconductive collar 231 described below. Gaskets 228, 230 and collar 231provide grounding contact with outer surfaces of the module assembly 102to facilitate electromagnetic shielding when the module assembly 102 isinstalled. To further prevent EMI leaks through front opening 136 ofguide frame 122, a gasket 233 (shown in FIG. 4) is positioned betweencollar 231 and an interior surface of bezel 108. Gasket 233 surroundsthe opening 109 in the bezel 108 and is compressed by the forward end ofthe guide frame 122 during assembly. In an exemplary embodiment, gasket233 is fabricated as a pad from a conductive foam material, such as thatcommercially available from Laird Technologies of Delaware Water Gap,Pa. The pad includes a hole or opening therethrough that is aligned withbezel opening 109 as the gasket 233 is installed and secured to a rearsurface of the bezel 108, such as with a known adhesive. The collar 231directly and compressively engages the gasket 233 and provides acontinuous EMI shield interface between the guide frame 122 and thebezel 108.

Additionally, referring back to FIG. 4, an intermediate EMI gasket 123is positioned forward of the receptacle connector 120 and also providesa grounding contact to the outer surface of the module assembly 102 toprovide EMI shielding in an intermediate portion of the module assembly102. Gasket 123 also contacts the ground surface 146 (shown in FIG. 1)of the host circuit board 106. EMI gaskets 232, 234 are further providedat the rear of the guide frame 122 for additional EMI shielding. Theforegoing EMI gasket features are further described in detail below.

FIG. 5 is a perspective view of the module assembly 102 partly insertedinto receptacle assembly 104 and in an unlatched or released position.Bail 182 is positioned in an unlatched position which, as describedbelow, causes actuator arms 184 to release from latch elements 196 inthe side walls 132, 134 of the guide frame 122. The receptacle connector120 is positioned in the rear of the cavity 138 in the guide frame 122,and the receptacle connector 120 is soldered to the host board 106.Guide frame 122 is electrically connected to the conductive surface 146(shown in FIG. 1) of the host board 106 to provide an electromagneticshielding cage about the module assembly 102 when coupled to thereceptacle connector 120 in the latched position. Intermediate EMIgasket 123 is located in a lower portion of the cavity 138 forward ofthe receptacle connector 120. A rear EMI gasket 232 is disposed aboutthe outer periphery of the rear end of the guide frame 122 adjacent thehost board 106.

FIG. 6 is a partly broken away perspective view of the receptacleassembly 104 with the module assembly 102 removed. The receptacleconnector 120 is positioned in the rear end of the cavity 138 to receivethe printed circuit board 220 (shown in FIG. 4) of the module assembly102 (shown in FIG. 4). Intermediate EMI gasket 123 extends upwardly fromthe bottom wall 130 of the guide frame 122 into the path of the moduleassembly 102 when inserted into the cavity 138 of the guide frame 122.Latch elements 196 extend inwardly from the side walls 132, 134 of theguide frame 122 into the cavity 138 and also into the path of the moduleassembly 102. A front end of the guide frame 122 includes an EMI gasketassembly 125 described below.

FIG. 7 is a perspective view of clip 152 which couples the heat sink 150to the guide frame 122 (shown in FIGS. 1-5). Clip 152 includes oppositeside rails 156 connected by spring members 155 extending from upperedges 280, and the side rails 156 each include engagement openings 198for interfacing engagement with tabs 154 (shown in FIGS. 1 and 2) in theside walls 132, 134 of the guide frame 122. Side rails 156 each furtherinclude a release aperture 284 that facilitates insertion of a tool,such as a screwdriver, to remove clip 152 from the side walls 132, 134of the guide frame 122. A screwdriver or other tool may be inserted inrelease aperture 284 to permit prying of the side rails 156 away fromthe guide frame 122, thereby releasing the rails 156 from beneath thetabs 154 and permitting removal of the clip 152 from the guide frame122. Side rails 156 further include outwardly flared lower edges 286 tofacilitate insertion of clip 152 over the sides of heat sink 150 and theside walls 132, 134 of the guide frame 122.

In an exemplary embodiment, the spring members 155 extend substantiallyvertically upward from the upper edges 280 of the side rails 156. Eachspring member 155 includes opposite elevated portions 288 extendingsubstantially perpendicular to respective side rails 156, and adepressed portion 290 extending between the elevated portions 288. Assuch, the spring members 155 may resiliently flex as the side rails 156are separated for installation to the guide frame 122, while providing asnug and secure fit to the guide frame 122.

FIG. 8 illustrates a heat sink assembly 300 including clip 152 fitted tothe heat sink 150. The heat sink 150 includes a number of heat transferpins 302 arranged in rows and columns and extending upwardly from agenerally rectangular base 304. Spring members 155 of clip 152 extendbetween selected rows of pins 302 that are spaced apart by gaps 303.Depressed portions 290 of spring members 155 contact the heat sink base304.

In the illustrated embodiment, four sections of pins 302 are providedand each section includes fifty-four substantially cylindrical pins 302extending upward from the base 304. Adjacent sections of pins 302 areseparated by one of three spring members 155 provided in clip 152. It isrecognized, however, that a greater or fewer number of pins, pinsections, and spring members may likewise be employed in alternativeembodiments of the invention. Additionally, it is understood that othershapes and configurations of pins 302, fins and/or bases 304 may beemployed in alternative embodiments of the invention.

FIG. 9 illustrates the heat sink assembly 350 coupled to the guide frame122 and with the module assembly 102 inserted therein. Heat sinkassembly 350 is installed over the cavity 138 in the guide frame 122 andthe tabs 154 in the side walls 132, 134 of the guide frame 122 arereceived in the apertures 198 in the side rails 156 of the clip 152. Theclip 152 positions a lower engagement surface 162 of the heat sink 150in the path of the module assembly 102. As shown in the broken awayportion of FIG. 9 (and also shown in FIG. 2), in an exemplary embodimentthe base 304 includes a lower peripheral surface 160 surrounding theengagement surface 162. The peripheral surface 160 is recessed withrespect to a plane containing the engagement surface 162, or in otherwords, the engagement surface 162 extends outwardly from the peripheralsurface 160 toward a top surface 384 of the module assembly 102. Theopposed lateral portions 186, 188, 190, 192 (shown in FIG. 3) of the topwall 128 of the guide frame 122 support the peripheral surface 160 ofthe heat sink 150 when the module assembly 102 is not installed.

As the module assembly 102 is inserted into the cavity 138 of the guideframe 122, the top surface 384 of the module assembly 102 upwardlydisplaces the engagement surface 162 of the heat sink 150 against thebias of clip 152. Consequently, the clip 152 provides a downward bias orpressure via spring members 155 to maintain the two surfaces 162, 384 incontact for optimal heat transfer therebetween. Ramped transitionportion 164 extends between the heat sink engagement surface 162 and theperipheral surface 160 to facilitate smooth engagement of the heat sinkengagement surface 162 and the top surface 384 of the module assembly102 during installation and removal from the receptacle assembly 104.Additionally, the engagement surface 162 is flat and smooth tofacilitate sliding insertion of the module assembly 102. While heattransfer between the heat sink 150 and module assembly 102 is providedthrough metal-to-metal contact of the module top surface 384 and theheat sink engagement surface 162, it is understood that a thermalinterface material could be incorporated in further and/or alternativeembodiments to enhance or alter the heat transfer relationship.

FIG. 10 illustrates another embodiment wherein the peripheral surface160 of the heat sink 150 resides on tabs 400, 402 that are formed alongthe top edge of each side wall 132, 134 of the guide frame 122. The heatsink 150 is secured to the guide frame 122 by spring members 404integrally provided with the side walls 132, 134. The spring members 404exert a downward biasing force on the heat sink 150. Unlike springmembers 155 (shown in FIGS. 1, 6 and 8), spring members 404 do notextend across the width of the guide frame 122, but rather only extendacross the heat sink 150 a sufficient distance to retain the heat sink150 in position.

In a further alternative embodiment, the guide frame 122 includesnotched out portions 406 (shown in phantom in FIG. 10) in the side walls132, 134 and/or the lateral portions 188-192 (shown in FIG. 3) of thetop wall 128 of the guide frame 122. In such an embodiment, the heatsink 150 rests on the edges of the side walls 132, 134 and/or thelateral portions 188-192 of the top wall 128 in the notched out portions406.

FIGS. 11-13 illustrate an EMI shielding gasket assembly 125 forshielding the forward or front end 422 of the guide frame 122 proximatethe bezel 108 (shown in FIGS. 1 and 3) to prevent undesirableelectromagnetic interference from leaking through the front end 422.Front end 422 includes a top edge 424, a bottom edge 426, and side edges428, 430 which are formed as flanges surrounding and defining an outerperiphery of the opening 136. Opening 136 provides access to cavity 138defined by the walls of the guide frame 122. An electrically conductivegasket 228, 230, 434, 436 is installed on each respective edge 424, 426,428, 430 of the front end 422. The gasket 228 is illustrated in aninstalled position over the top edge 424 in FIG. 11, and FIG. 13illustrates the gasket assembly 125 installed to the front end 422.

Each of the gaskets 228, 230, 434, 436 is bent so that it extendsthrough the opening 136 and partially into the interior cavity 138 ofthe guide frame 122 when the gaskets are installed, as best illustratedin FIG. 13. Each gasket 228, 230, 434, 436 has resilient straps 438 ofan arched configuration, and the straps 438 contact the module assembly102 in the top, bottom and side walls of the module assembly 102 toprovide a barrier for EMI. The flanges or edges 424-430 with the gaskets228, 230, 434, 436 fitted thereon are abutted against the bezel 108 ofthe electronic host equipment. That is, the gaskets 228, 230, 434, 436are sandwiched between respective flanges 424-430 and the bezel 108,with the front opening 136 in the guide frame 122 being aligned with anopening 109 (shown in FIGS. 1 and 4) in the bezel 108 to permitinsertion of the module assembly 102 into the guide frame 122.

The gaskets 228, 230, 434, and 436 are adapted to reduce any gapsbetween the flanges 424-430 and the bezel 108, and also to reduce anygaps between the module assembly 102 and the guide frame 122, in orderto prevent leakage of EMI. Such EMI may be generated internally by themodule assembly 102, or externally by devices of the host equipment. Thegaskets 228, 230, 434, 436 are connected to electrical ground, firstthrough engagement with the bezel 108 which is grounded to the hostchassis, and also through the guide frame 122 which has pins or leads142 that are connected to ground on the host board 106 on which theguide frame 122 is mounted (as best illustrated in FIG. 1). Thus, EMIwhich impinges on the guide frame 122 or on the gaskets 228, 230, 434,436 is effectively directed to electrical ground.

More particularly, in an exemplary embodiment, gaskets 228, 230, 434,436 are fabricated from a conductive material such as thin copper alloysheets. Top and bottom gaskets 228, 230 extend substantially the lengthof top and bottom edges 424, 426, respectively, of the front end 422 ofthe guide frame 122. Top and bottom gaskets 228, 230 are mirror imagesof one another when installed on the front end 422, and each of the topand bottom gaskets 428, 430 includes a bridge 440 that overliesrespective edges 424, 426, a clip section 442 that hooks over therespective edge 424, 426, and straps 438 extending from the bridge 440on an opposite side of the hook portion 442. The clip section 442 formsa groove which hooks over an exterior surface of the front end 422 ofthe guide frame 122. As best seen in FIG. 13, the straps 438 are curvedand extend inwardly into the opening 136 while a distal end thereof isflared outwardly with respect to the opening and is in contact with arespective one of the side walls 132, 134 of the guide frame 122. Whilein the illustrated embodiment, eight straps 438 are provided on each ofthe top and bottom gaskets 228, 230, it is recognized that greater orfewer straps 438 may be provided in further and/or alternativeembodiments. By substantially covering a majority of the top and bottomedges 440, 442 with gaskets 228, 230, a shielded EMI interface isprovided along the top and bottom edges 440, 442.

Similarly, left and right gaskets 434, 436 are mirror images of oneanother when installed on the front end 422, and each of the left andright gaskets 434, 436 includes a bridge 444 that overlies respectiveleft and right edges 428, 430 of the front end 422, a clip section 446that hooks over the respective left and right edge 428, 430, and straps438 as described above extending from the bridge 444 on an opposite sideof the hook portion 446. The clip section 446 forms a groove which hooksover an exterior surface of the front end 422 of the guide frame 122.While in the illustrated embodiment, three straps 438 are provided oneach of the left and right gaskets 434, 436, it is recognized thatgreater or fewer straps 438 may be provided in further and/oralternative embodiments. By substantially covering a majority of theleft and right edges 428, 430 with gaskets 434, 436, a shielded EMIinterface is provided along the left and right edges 428, 430.

In a particular embodiment, adjacent straps 438 of gaskets 228, 230,434, 436 are separated from one another by narrow slots of about 1 mm orless, and the straps 438 include widths that are substantially greaterthan widths of the slots to provide adequate EMI shielding for datatransmission rates of 10 Gbs. It is recognized, however, that relativedimensions of the slots and widths of the straps may be varied inalternative embodiments.

Gaskets 228, 230, 434, 436 are separately secured to the front end 422of the guide frame 122 forming the opening 136. Specifically, thegaskets 228, 230, 434, 436 are attached to the front end 422 viaengagement openings 446 that align with openings 448 in the front end422 of the guide frame 122. The collar 231 receives the bridge 440, 444of the gaskets 228, 230, 434, 436, and includes retaining pins or tab450 which extend through openings 446, 448 and connects the gaskets 228,230, 434, 436 to the front end 422. The collar 231 is secured over thefront end 422 of the guide frame 122 and the collar 231 encloses theedges of the front end 422, the bridges 440, 444, and a portion of theclip sections 442, 446 to secure the EMI gaskets 228, 230, 434, 436 tothe guide frame 122.

Collar 231 includes a flat and smooth outer surface 452 that provides anuninterrupted and continuous EMI shielding interface with a bezel 108.Additionally, the outer surface 452 of the collar 231 compressivelyengages a gasket 233 (shown in FIG. 4) that is fastened to the interiorsurface of bezel 108 (shown in FIGS. 1 and 4).

In an exemplary embodiment, the collar 231 is fabricated from aconductive material, such as aluminum or zinc in a known die-castingoperation. In alternative embodiments, collar 231 may be fabricated fromother known materials and according to other processes and techniquesfamiliar to those in the art. As shown in FIGS. 11 and 12, the collar231 is formed into a complementary shape to the front end 422 of theguide frame 122, and thus in the illustrated embodiment is substantiallyrectangular. Retaining pins 450 extend inwardly from a flat inner groove460 that receives the forward end 422. The pins 450 extend slightly intothe opening 462 through the collar 231. A lip 464 is formed adjacent aperimeter of the opening 462 which abuts respective portions of thegaskets 228, 230, 434, 436 when the collar 231 is installed, as shown inFIG. 13.

FIG. 14 illustrates an alternative embodiment wherein the front end 422of the guide frame 122 includes separately provided gaskets 468 coupledto each of the edges the front end 422. The gaskets 468 include flanges469 extended outwardly from the edges of the front end 422 in asubstantially perpendicular fashion. The flanges 468 are configured toabut gasket 233 (shown in FIG. 4) that is secured to the bezel 108(shown in FIGS. 1 and 4) to provide EMI shielding for the front end 422.A number of notches 470 are formed into the walls of the guide frame 122adjacent the gaskets 468. The notches 470 receive straps of the gaskets468 which extend into the interior of the guide frame 122 and providegrounding contact with the module assembly 102 in the manner describedabove.

FIG. 15 is a bottom perspective assembly view of the receptacle assembly104 as it interfaces with the host board 106 (shown in FIG. 1) in thevicinity of the receptacle connector 120 (shown in FIG. 1). Asillustrated in FIG. 4, printed circuit board 220 (shown in FIG. 4)within the module assembly 102 is engaged with the connector receptacle120 in a bottom rear of the guide frame 122 Referring back to FIG. 15,an electromagnetic interference shielding gasket assembly 480 isaccordingly provided in the bottom rear of the guide frame 122.

A rear cap 482 is attached to a rear of the guide frame 122 to close offan opening 484 through a bottom wall 130 of the guide frame 122.Intermediate EMI gasket 123 is provided along a forward or leading edge485 of the opening 484, and the intermediate gasket 123 includes contactstraps 486 extending into the cavity 138 in a similar manner to thosedescribed above. The contact straps 486 extend along the leading edge485 of the opening 484 as the module assembly 102 is inserted into theguide frame 122, as also illustrated in FIGS. 4 and 5. The straps 486have widths sufficient to cover a substantial majority of the leadingedge 485 to form a shielded interface along the leading edge 485. Thestraps 486 brush a bottom surface of the module assembly 102 as themodule assembly 102 is inserted into the guide frame 122. The straps 486are deflected by the module assembly 102 and provide a conductive pathfrom the module assembly 102 to the chassis ground of the hostequipment. In an exemplary embodiment, the straps 486 establish anelectrical path to the conductive surface 146 (shown in FIG. 1) of thehost board 106, which is in turn electrically connected to an electricalground.

A lower rear EMI gasket 232 is provided extending along the rear cap 482and side portions 492, 494 of the opening 484 to provide further EMIshielding. In an exemplary embodiment, the gasket 232 is fabricated froma rubber elastomer containing conductive particulate material and formedinto a U-shaped skirt fitting the rear end of the guide frame 122. Agroove 488 is formed in gasket 232 which receives an edge of the guideframe 122, as also illustrated in FIG. 4. The gasket 232 includes astepped contour in cross section that extends along different parallelplanes on either side of the groove 488. The gasket 232 is compressibleand compressed against the conductive surface 146 (shown in FIG. 1) onthe host board 106 (shown in FIG. 1) to form a continuous anduninterrupted shielded interface along the side and rear edges of thebottom opening 484 when the guide frame 122 is installed to the hostboard 106 (shown in FIG. 1).

In an illustrative embodiment, the EMI gasket 232 includes a flexiblebase portion 490 fitting along the side edges 492, 494 of the bottomopening 484 and configured to rest on the conductive layer 146 (FIG. 1)provided on the host board 106 (FIG. 1). The base portion 490 is formedintegrally with a series of flexible serrated teeth 496 on interiorsurfaces thereof. The teeth 496 project upward into the interior cavity138 of the guide frame 122 through the bottom opening 484. The serratedteeth 496 are disposed adjacent each of the side walls 132, 134 of theguide frame 122 in the interior of the cavity 138 of the guide frame122. The serrated teeth 496 extend from the bottom opening 484 into theinterior cavity 138. As such, the serrated teeth 496 are oriented toengage the module assembly 102 when installed into the guide frame 122.

An upper EMI gasket 234 is disposed within the interior cavity 138 ofthe guide frame 122 proximate a rear end of the guide frame 122. In theillustrated embodiment, gasket 234 is a conductive foam pad adhered tothe rear cap 482 of the guide frame 122 and in an abutting relationshipwith lower EMI gasket 232. Conductive foam materials suitable forfabrication of the gasket 234 are commercial available, for example,from Laird Technologies of Delaware Water Gap, Pa.

By separately providing EMI gaskets 123, 232, 234 on the front edge 485,the side edges 492 and 494 and the rear cap 482 of the bottom opening484, effective EMI shielding is provided about the interface between thereceptacle connector 120 and the module assembly 102.

FIG. 16 is a front perspective assembly view of the module assembly 102shown in FIGS. 1 and 3-5 illustrating an ejector mechanism 180 formed inaccordance with an embodiment of the invention.

The module assembly 102 includes a pair of actuator arms 184 which aremirror images of one another and cooperate with a bail 182 to releasethe module assembly 102 from the latched position and to eject themodule assembly 102 from the receptacle assembly 104 (shown in FIG. 1).Bail 182 is a generally rectangular body having a top side 500, a bottomside 502, and left and right sides 504, 506 defining an opening 508which is dimensioned to receive the connector interface 124 of themodule assembly 102. The connector interface 124 includes a slot 510formed in a lower end thereof, and the bottom side 502 of the bail 182is received in the slot 510 to pivotally mount the bail 182 to themodule assembly 102. An angled foot portion 512 extends from each thelower corners of the bail 182 at the intersection of the bottom side 182and the left and right sides 504, 506.

The actuator arms 184 include a main body portion 514 including anaxially extending ejector tab 516, and a foot portion 520 extendingsubstantially perpendicularly to the main body portion 514. A latchedcontact stop portion 522 extends on an opposite end of the main body 514from the ejector tab 516 and extends outwardly from a forward end 524 ofthe foot portion 520. The main body portion 514 includes a steppedcontour 526 on an interior surface 527 thereof and a tapered leading end528 on an exterior surface 529. The tapered leading end 528 has agradually reduced thickness to form a ramped surface extending to theejector tab 516. The ejector tab 516 has a reduced width relative to themain body portion 514 and includes a ramped surface 530 extending to araised boss 532.

The ramped surface 530 of the ejector tab 516 is inclined oppositely tothe tapered leading end 528 of the actuator arm 14. That is, whiletapered leading end 528 is reduced in thickness in an axial orlongitudinal direction of the main body 514, the ramped surface 530 ofthe ejector tab 516 is increased in thickness from the leading edge 528of the main body 514 to the boss 532 of the ejector tab 516. Thus, in agiven orientation, if the tapered end 528 has a positive slope, theramped surface 530 has a negative slope, or vice-versa. As illustratedin FIG. 16, the tapered end 528 and the ramped surface 530 are arrangedside-by-side in a valley configuration and thus are sloped toward oneanother. Also, the angle of inclination of the ramped surface 530 issubstantially steeper than the angle of inclination of the tapered end528. The interior surface 527 of each actuator arm 184 includes alongitudinal slot 534 which houses a bias element 536, such as a coilspring an exemplary embodiment. The bias element 536 providesspring-loaded release actuation of the module assembly 102 as the bail182 is manipulated by a user.

The module assembly 102 includes a retention cavity 540 on each of theside walls 538, 539 thereof, and the retention cavities 540 are shapedgenerally complementary to the outer profile of the respective actuatorarms 184. Thus, each of the retention cavities 540 includes a firstportion 542, a second portion 544, and a third portion 546. The firstportion 542 has a width slightly larger than a width of the main bodyportion 514 of the actuator arm 184 and a depth substantially equal to afill depth of the main body portion 514 (i.e., the depth of the thickerportion of the stepped contour 527 of the actuator arms 184). The secondportion 544 has a width substantially equal to the first portion but adepth substantially equal to the reduced depth of the main body portion514 adjacent the tapered leading end 528 (i.e., the depth of the thinnerportion of the stepped contour 527 of the actuator arms 527). The thirdportion 546 has a substantially equal depth to the second portion 544but a reduced width that is slightly larger than a width of the ejectortab 516. The first and second portions 542, 544 of the retention cavity540 are configured to accept the stepped contour 527 of the main bodyportion 514 of the actuator arms 184, and the third portion 546 isconfigured to receive the ejector tab 516 with sliding engagement. Ashoulder 548 separates the first portion 542 from the second portion 544and provides an abutment or seat for the bias element 536 of theactuator arm 184.

When actuator arms 184 are received in the respective retention modulecavities 540 of the module assembly 102 and when the bail 182 is mountedto the connector interface 124 and rotated upward so that foot portions512 of the bail 182 contact the foot portions 520 of the actuator arms,the ejector mechanism 180 is engaged and ready for use.

FIG. 17 is a side elevational view of the module assembly 102 with theactuator arms 184 received in the retention cavity 540 and the bail 182in the latched position. As the module assembly 102 is inserted into thereceptacle assembly 104, the retention tabs 516 contact the latchelements 196 (shown in FIGS. 4 and 5) of the guide frame 122 (shown inFIGS. 4 and 5) and deflect the latch elements 196 outwardly to allow themodule assembly 102 to be inserted into the guide frame 122 (FIGS. 4 and5). When the module assembly 102 is fully inserted, the retention tabs516 clear the latch elements 196, and the latch elements 196 deflectinwardly and rest upon the tapered leading ends 528 of the actuator arms184. The retention tabs 516 therefore become latched behind the latchelements 196 of the guide frame 122 when the module assembly 102 isfully installed in the guide frame 122.

In the latched position, the bail 182 is positioned substantiallyupright with the foot portions 512 of the bail 182 contacting the footportions 520 of the actuator arms. The latched contact stop portions 522of the actuator arms 184 contact the sides 504, 506 (shown in FIG. 16)of the bail 182. The bias element 536 (shown in FIG. 16) is loaded incompression and maintains the bail 182 in the latched position. Footportions 512 of the bail 182 extend at an obtuse angle relative to sides504, 506 (FIG. 16) of the bail 182 and are rounded at the point ofcontact with the foot portions 520 of the actuator arms 182.

FIG. 18 is a side elevational view of the module assembly 102illustrating the ejector mechanism in a first intermediate position asthe bail 182 is pivoted about its lower end 502 to actuate the mechanismand release the module assembly 102 from the receptacle assembly 104.The bail 182 is pivoted away from the interface connector 124 (clockwisein FIG. 18) about its lower end, and the foot portions 512 of the bail182 slide upwardly against the foot portions 520 of the actuator arms184. The angled foot portions 512 cause the actuator arms 184 to movelongitudinally inward (to the left in FIG. 18) into the retentioncavities 540, thereby further loading the bias elements 536 in theactuator arms 184.

FIG. 19 is a side elevational view of the module assembly 102illustrating the bail 182 pivoted to a second intermediate positionwherein the foot portions 512 of the bail 182 are positioned relative tothe foot portions 520 of the actuator arms such that the bias elements536 are compressed to a maximum load. Further pivoting of the bail 182from this position permits the bias elements 536 to relax and push theactuator arms 184 forward toward the connector interface 124. At thispoint, the latch elements 196 of the guide frame 122 are in contact withthe ramped surfaces 530 of the ejector tabs 516 of the actuator arms184. As the bias elements 536 force the actuator arms 184 in a forwarddirection (to the right in FIG. 19), the ramped surfaces 530 deflect thelatch elements outwardly until the boss 532 clears the latch elements196.

FIG. 20 is a side elevational view of the module assembly 102illustrating the bail 182 in an unlatched position wherein a flat bottomsurface 560 of the bail foot portions 512 are flush against the footportions 520 of the actuator arms 184. The actuator arms 184 aredisplaced forwardly by the bias elements 536, and the retention tabs 516are released from the latch elements 196 of the guide frame 122. In theunlatched position, the module assembly 102 may be removed from thereceptacle assembly 104 by pulling the bail 182 to slide the moduleassembly 102 out of the receptacle assembly 104. The bias elements 536maintain the bail 182 in the latched position until the bail 182 isactuated to the latched position described above.

The bail 182 is pivoted back toward the connector interface 124 toposition the actuator arms 184 back to the latched position (shown inFIG. 17) wherein the retention tabs 516 may be engaged to the latchelements 196 (FIGS. 4 and 5) of the receptacle assembly 104.

FIG. 21 illustrates an alternative embodiment of an ejector mechanism600 for releasing a module assembly 602 from the receptacle assembly 104described above. The module assembly 602 includes a base 604, a printedcircuit board 606, and a cover 608 with an attached connector interface610. Printed circuit board 606 is configured for transceiver functionsand is capable of 10 Gbs data signal rate transmission, and the moduleassembly 602 interfaces with the receptacle connector 120 of thereceptacle assembly 104 as described above.

The cover 608 includes a flat bottom wall 612 and opposite side walls614, 616 extending substantially perpendicular to the bottom wall 612.Notches or cut-outs are formed in the, leading edges of the side walls614, 616 which receive an actuator 620. The actuator 620 includes twolongitudinal members or actuator arms 622, 624 including respectiveoutwardly extending ejector tabs 626, 628 extending therefrom, andrespective resilient re-set bias elements 630, 632 extending axially andintegrally with the actuator arms 622, 624. The actuator 620 includes across bar 640 extending between the actuator arms 622, 624, and thecross bar 340 extends beneath the connector interface 610 when theactuator 620 is installed. Clips 642, 644 extend forwardly from thecross bar 640 and provide a bracket for receiving foot portions 646 of abail 636 to pivotally mount the bail 636 to the module 602.

In the illustrated embodiment, the actuator 620 is a stamped metal partformed as a single-piece unit such that the bias elements 630, 632 aresubstantially coplanar with the actuator arms 622, 624 in a serpentineconfiguration. It is understood, however, that actuator 620 could inalternative embodiments be fabricated from multiple pieces and a varietyof materials according to known processes and techniques.

When the module assembly 602 is assembled and fully inserted into theguide frame 122 (FIGS. 4 and 5), the retention tabs 196 (FIGS. 4 and 5)on the guide frame 122 enter respective cavities 634 in the moduleassembly cover 608, thereby preventing withdrawal of the module assembly602 from the guide frame 122. Pulling on the bail 636 extends the biaselements 630, 632 and causes angled surfaces on the ejector tabs 626,628 to deflect the latch elements 196 (FIGS. 4 and 5) outwardly, therebyremoving the latch elements 196 from the module assembly cavities 634and permitting withdrawal of the module assembly 602 from the guideframe 122. When the bail 636 is released the bias elements 626, 632 areunloaded and return the ejector tabs 622 to their normal position inengagement with rear edges 638 of the notched portions 618 of the cover608.

While the invention has been described in terms of various specificembodiments, those skilled in the art will recognize that the inventioncan be practiced with modification within the spirit and scope of theclaims.

What is claimed is:
 1. A receptacle assembly, comprising: a guide framehaving a front end with an opening to an interior cavity of said guideframe, said opening being configured to receive a module assembly, saidguide frame having a bottom with a bottom opening to said interiorcavity, said bottom being configured to be joined to a circuit board;and an EMI gasket provided along at least a portion of a perimeter ofsaid bottom opening to be held between said guide frame and a circuitboard, said EMI gasket forming a shielded interface along said portionof said perimeter of said bottom opening.
 2. The receptacle assembly ofclaim 1, wherein said EMI gasket includes a series of conductive strapsprovided along a leading edge of said bottom opening nearest said frontend, said conductive straps being provided along said leading edge andhaving widths sufficient to cover a substantial majority of said leadingedge to form said shielded interface along said leading edge.
 3. Thereceptacle assembly of claim 1, wherein said EMI gasket includes a skirtextending partially along said portion of said perimeter of said bottomopening, said skirt being formed of a rubber elastomer containingconductive particulate material.
 4. The receptacle assembly of claim 1,wherein said EMI gasket comprises a skirt having a groove formedtherein, said bottom opening having an edge, at least a portion of saidedge fitting in said groove.
 5. The receptacle assembly of claim 1,wherein said EMI gasket includes a U-shaped skirt fitting over sideedges and a rear edge of said bottom opening, said skirt beingcompressible to form a continuous and uninterrupted shielded interfacealong said side and rear edges of said bottom opening.
 6. The receptacleassembly of claim 1, wherein said EMI gasket includes a flexible baseportion fitting along an edge of said bottom opening, said base portionbeing formed integrally with a series of flexible serrated teeth thatproject upward into said interior cavity through said bottom opening,said serrated teeth being positioned along an interior surface of a sidewall of said guide frame.
 7. The receptacle assembly of claim 1, whereinsaid EMI gasket includes a conductive elastomer skirt provided along arear edge of said bottom opening and includes an upper conductive foampad provided on said skirt, said pad being held within said interiorcavity proximate a rear end of said guide frame.
 8. The receptacleassembly of claim 1, wherein said EMI gasket includes flexible serratedteeth provided along side edges of said bottom opening, said serratedteeth extending from said bottom opening into said interior cavity, saidserrated teeth being oriented to engage a module assembly when installedinto said guide frame.
 9. The receptacle assembly of claim 1, whereinsaid EMI gasket is configured to engage a transceiver module assemblyabout an opening in a front end of the transceiver module assembly. 10.The receptacle assembly of claim 1, wherein said EMI gasket iscompressible between said guide frame and the circuit board.
 11. Atransceiver receptacle assembly comprising: a guide frame having a frontend with an opening to an interior cavity of said guide frame, saidopening being configured to receive a transceiver module assembly, saidguide frame having a bottom with a bottom opening to said interiorcavity, said bottom configured to be mounted to a conductive layerprovided on a circuit board, said bottom opening being configured toreceive a receptacle connector mounted to the printed circuit board; andan EMI gasket provided along at least a portion of an edge of saidbottom opening, said EMI gasket being compressible between said guideframe and the conductive layer on the circuit board.
 12. The transceiverreceptacle assembly of claim 11, wherein said EMI gasket includesconductive straps provided along one edge of said bottom opening, saidconductive straps being deflectable by a transceiver module assembly todirectly engage the conductive layer of the circuit board.
 13. Thetransceiver receptacle assembly of claim 11, wherein said EMI gasketincludes spring contacts closely spaced proximate one another along afirst edge of said bottom opening and a conductive foam layer providedalong a second edge of said bottom opening.
 14. The transceiverreceptacle assembly of claim 11, wherein said EMI gasket includesseparate front, rear, and side EMI gaskets provided along respectivefront, rear and side edges of said bottom opening.
 15. The transceiverreceptacle assembly of claim 11, wherein said EMI gasket forms ashielded interface surrounding said bottom opening, said shieldedinterface having a stepped contour that extends along different parallelplanes.
 16. The transceiver receptacle assembly of claim 11, whereinsaid EMI gasket includes opposed side gaskets formed of an elastomercontaining conductive particulate material.
 17. The transceiverreceptacle assembly of claim 11, wherein said EMI gasket includes alinear continuous base surface configured to rest on a conductive layerprovided on a circuit board.
 18. The transceiver receptacle assembly ofclaim 11, wherein said EMI gasket includes first and second portionsoriented perpendicular to one another and having smooth lower surfacesconfigured to rest on a conductive layer provided on a circuit board.19. The transceiver receptacle assembly of claim 11 further comprising acircuit board with a conductive layer provided thereon, said guide framebeing directly mounted to said conductive layer.
 20. The transceiverreceptacle assembly of claim 11 further comprising a circuit board witha receptacle connector mounted thereto, said guide frame being mountedto said circuit board with said receptacle connector extending upwardinto said bottom opening, said EMI gasket surrounding said receptacleconnector.